Porous article of bonded granular material



EXAMINER POROUS ARTICLES OF BONDED GRANULAR IATERIAL Dern 1, 1942Patented Dec. l., 1942 sans l ori-lcs PROUSV ARTICLE F BONDED Gm l'MATERIAL hankLGcllnagWaonsaMlJ.

This invention relates to light-weight mrous vawlegfand in particular torigid, porous bodies composed of granular material nrmly bound togetherinto an integral structural unit by cementitious material and capable ofbeing cast or molded into such products from a plastic or a wet mix ofthe materials: and has for one o! its objects the production oi' moldedporous products such as, for example, porous pipe and various moldedporous articles-in slab form, which are 4 eable to the adapted fory useas ltcrs, for drainage Purposes and the like.

Another object of the invention is to provide a novel and superiorcomposition which is highly useful tor making molded or cast porousarticles, such as, for example, castable pipe and slab-like bodiespossessing lighter weight than other forms of molded products now on themarket for drainage purposes and for tiltering purposes, and of which Iam aware.

Another object of the invention is to provide a rigid, fully porous.acid-proof article which will possess a relatively high degree ofuniformity in structure and a controllable permeability.

Another object of the invention is to provide cast porous products ofvarious degrees of permeability, as desired, and in particular to make aporous pipe or a slab-like porous medium which has a relatively uniformpermeable structure throughout its extent of either fast or slowdrainapplication December so, mo, semi No. siam v1 claim.' (ci.'sie-ess) Fig. Us a fragmentary detail sectional view, on enlarged scaleof the wall structure of either of the embodiments shown in Figs. 1 and2 show.. ing the fully permeable character of the walls; and

l'ig. 5 is a perspective view, on reduced scale, oi' a slab-like articlefor filtering purposes consisi-usted in accordance with the presentinven-b tion.

l0 Rigid porous articles which are permeable to passage of liquids andgases, and which are adapted for use as nltering and diffusion mediumsin various chemical and industrial proccases and for. nltering purposesin general, are

l5 known, but these prior porous articles are ex.

age or filtering qualities as desired, high strength and capable ofbeing easily manufactured at low cost. Y Another object of the inventionis themanufacture of pipe of relatively uniform permeability utilizing aporous granular material as the aggrepensive and they have comprisedmineral gran.- ules 4of a refractory material, such as a crystallinealumina or silicon carbide united into a rigid integral porous structureby' a vitrined ce- 20 ramic binder, auch as a mixture of ball clay, slipclay and feldspar proportioned and treated as is well known in theceramic art during which treatment the bond is lyited to a heattreatment at elevated temperatures to vitrify the bond.

It is desirable, however, to provide a rigid porous article oi' a Vfullypermeable structure of simple and inexpensive construction comprisinggranular material bound together by a settable cemcntitious materialinto an integral porous 0 mass and to utilize waste material as theaggregate and in a degree of sub-division according to the particularpermeability and strength desired and use for which the article isintended,

manufacture of rigid porous articles of a pergate therein consisting gfglie in ilne and coarse sizes` bonded into en integrLRQmuL e With theseand other 'bjects in view, as will be apparent from the followingdisclosure, the invention resides in the composition of matter and theconstructions herein described and as set forth in the speciication fandcovered by the claim appended hereto. Y.

In the accompanying drav'iig: Fig. 1 is a central longitudinal view, onreducedscal'z, of a drainage pipe of the bell end o type embodying thepresent invention; g y

Fig. 2 is a central longitudinal view, also on reduced scale,` of adrainage pipe of the tongue and groove style embodying the invention;

Fig. 3 is'a transverse sectional view taken approximately on' the line3-3 of Fig. l;

One aspect of the invention contemplates the meable structure for usefor various drainage and filtering purposes, and in this connection itis particularly directed tothe making of a light weight porous pipe andof various porous slab- 40 like articles which have relatively uniformand controlled permeability and are especially adapted for use invarious sub-surfaiu'` drainage systems to replace the usual forms ofdrain pipe commonly used insuch systems.

It is therefore the aims of the present rinvention to provide rigidmolded porous articles of the above character having the desirablequalities oi .#controlled and uniform permeability,

' great lightness, high strength .and low cost of manufacture by thenovel structure of such articles and the composition of which they are vmade.

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making up the aggregate as well as by the pxog portion of tine andcoarse particles utilized as the aggregate and by the use of definiteproportions of a cementing agent, a fully permeable porous medium may beproduced possessing a relatively uniform porous structure and in whichthe permeability is relatively uniform and capable of passing uidseiliciently over a wide range from rapid to slow rates of ilow, asdesired.

In carrying out my invention I prefer to use' as an aggregate, crushedcoke in the form of a 1s 'mixture of relatively coarse lumps and finersize particles, bonded into a rigid integral porous fully permeablestructure by a suitable settable cementitious binder, 51h11 as. for examrtland cementndihealike. To these ends, I employ granular coke materialof a desired size or sizes bonded into a porous structure by thePortland cement and the like, set -and cured in the presence of thegranular aggregate, the bond adhering locally to the aggregateconnecting posts and webs therebetween and intergranular spaces or voidsof various sizes which intercommunlcate to form passages through thebonded structure of the porous medium to permit the ilow of huidtherethrough. Three em- :in

bodirnents of my invention are shown in Figs. 1, 2 and 5 of theaccompanying drawing, in which there is shown in Figs. 1 and 2 centrallongitudinal sections of two forms of pipe having a fully porouspermeable structure while Fig. 5 illus- 35 trates a slab provided withthis permeable structure. As illustrated in Fig. 4, in which there is.represented on enlarged scale the porous permeable structure of theembodiments shown in Fiss.

1, 2 and 5, the individual coke bodies Il! have 40 their surfaces coatedwith the cement layer i2 which may contain coke dust to provide tinelaments entering the surface pores of the coated coke granules and alsoforming the posts or webs i3 between adjacent coke bodies to connectthem 45 together and leave the intergranular voids I4 which form fluidpassages through the medium.

As a specific and illustrative example of a composition suitable for mypurposes, I may use a n g l v0 l Y are mixed with water to form acastable or moldable mass which is shaped as desiredfand hen dried, set

and cured with the proper amount of moisture to solidify the bond andunite the aggregate into an integral porous mass. The coke aggregateused may be olilrgsmmr it may consist of a mixture oww coke bodies andto include t at obtained in the "form known as breeze," which ispreierably used in l conjunction with larger lumps, such as.' forexample. those of. pea size. The strength of the molded porous m ums,such as pipe, made of 55 this composition by the use of both "breeze"and pea size" coke aggregate will be much eater than by the use ofeither the ilne slzirkthe coarse size alone with the cement binder. The

ratio of cokLtg cem a im varied widely other words. the permeability ofthe pipe is in u and forming coke-cement mixture consisting of threepuis 50 of coke aggregate and one part o Portland direct proportion tothe i'lnal physical structure of the porous walls of the pipe or thebody of other rigid porous media made of my composition, as well asbeing controlled also by the size and porosity of the coke aggregateused, and the amount of bond employed which should be sumcient tocompletely cover all the l;ggregate.

Ii' desired, suitable reinforcing steel may be incorporated in themolded products. and in the manufacture of pipe a steel helix or steelreinforcing rods may be placed therein in order to give additionalstrength to the pipe.

In the preferred practice. the cement binder and the coke aggregate,madeup of coke breeze" and larger` lumps of coke ificellaneous o coatthe su ace of each of the coke mrmmsas nearly so as may be practical.prior to the addition ofater to the mixture-"tftethis Tiihas beenthoroug caused to take place in the manner Just described, water israduLllMo the A while constantly stirring the mixture, and sum ientwater is added until mass attains the n of mortar or acq res suc aconsistency that it can, e re o a mold and allowed to harden, or it candry sumciently to be removed from the mold after being cast and allowedto harden. It can also be poured in either a stationary or in anagitating type of mold as ordinary concrete and allowed to set either ina steam heated curing vault or permitted to dry, set and be cured withthe proper amount of moisture under ordinary atmospheric conditions aspracticed in the treatment of regular cement mixtures.

It is further found that by causing the mixture to take place in thismanner by first stirring the ingredients to provide a uniform mixturewhile the particles are dry, the cement-coated coke upon being wettedwith the water seems to draw the cement and une coke dust into thesurface pores of the larger coke pieces which become filled with thefluid mass of cement and coke to form une hair-like illaments thereinwhich become tenaciously anchored to the coke lumps and act tomaterially bond the adjacent coke bodies together into a rigid integralmass when dried. set and cured withl the proper amount of moisture.

When the molded porous articles, thus described, and composed of thecoke and cement material, are put under tensile strain it is found theinvention as hereinafter deilned by the appended claim.

Having thus described my invention. what I claim as new and desire tosecure by Letters Patent is:

a mtering medium consisting of a,r nc1ded.un burned, porous bodycomposed principally o! codke in the form of pea-size lumps which areinxrspersed with assorted coke bodies of smaller size including cokedust, and a lessor quantity of Portland cement uniting said cokeaggregate into a rigid integral structure, sald cement binder 'beingpresent only in an amount to completely ing nuid passages through thebody whereby it will be completely permeable to nuids from one side ofthe body to the other side thereof. said cement coating containing cokedust and forming non-porous tlne hairlike filaments which enter into theexterior pores of the coated coke lumps and are Ilrmly anchored tc saidlumps.

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